SAO PAULO -- Brazil's replacement for the vuvuzela is giving World Cup organizers a headache.

It wasn't the sound of the caxirola -- a maraca-like instrument not nearly as noisy as the South African vuvuzela -- that attracted attention Sunday during its official debut at a match in northeastern Brazil. Instead, hundreds of the small green-and-yellow plastic objects were thrown onto the field by fans upset with their team's performance, forcing a brief interruption.

The incident came less than two months before the Confederations Cup begins in June.

Brazil Sports Minister Aldo Rebelo said it was "not good news" to see the instruments thrown by fans but hopes it is an isolated incident.

"It doesn't mean that something like this will happen if Brazil is losing a match during the World Cup," Rebelo said.

The protest also came less than a week after Brazil's national team was loudly jeered by nearly 50,000 fans in a 2-2 home tie against Chile in Belo Horizonte.

Created by Brazilian artist Carlinhos Brown, the caxirola was presented earlier this month and recognized by the Brazilian government and FIFA as the official fan instrument of the World Cup. It creates a continuous rattling sound that's softer than the one produced by the vuvuzelas in South Africa.

The hand-sized caxirola is based on the African instrument caxixi, which is played during the Capoeira, a popular afro-Brazilian martial art.

Brazilian President Dilma Rousseff was present for the official announcement, saying the instrument would come in handy to "to celebrate the goals, to celebrate our athletes" at next year's World Cup.

But the criticism has started early.

It's feared the hissing sound produced by thousands of caxirolas shaken at the same time will create a nuisance like the vuvuzelas did at the 2010 World Cup in South Africa, an issue that forced FIFA to address the noise produced by the long plastic horns. Critics also say the caxirola will produce an atmosphere not characteristic to soccer matches in Brazil, which are dominated by chants and percussion instruments.

"As predicted, in addition to the noise just as annoying as the one from the South African vuvuzelas, the caxirolas ended being thrown onto the pitch by disappointed fans watching their team lose," Brazilian sports columnist Juca Kfouri said. "It's another invention for clubs to worry about when it comes to the fans' lack of education."

Several thousand caxirolas were distributed to the nearly 30,000 people who attended the match between Bahia and Vitoria at Arena Fonte Nova in Salvador, among six stadiums hosting matches during the World Cup warmup tournament from June 15-30.

The caxirolas were hurled by Bahia fans near one of the sidelines after Vitoria scored its second goal in a 2-1 victory. No one appeared to be hit by the instruments, and Bahia's players cleared the field themselves, kicking and throwing the instruments away.

"The caxirola is licensed by FIFA, and this situation needs to be analyzed by security authorities to find out what needs to be done," said Ricardo Trade, CEO of the local 2014 World Cup organizing committee. "It's also a matter of culture. There is a need to re-educate the public."

At the African Cup of Nations in January, Ethiopia's soccer federation was fined $10,000 after the team's fans hurled vuvuzelas onto the pitch during one of the matches.